gen-readme.yml

name: Generate README
on:
  push:
  pull_request:
    paths:
      - "README.md" # This isn't needed, but it's a good sanity check
      - "README.tmpl.md"
  workflow_dispatch:
jobs:
  generate-readme:
    runs-on: ubuntu-latest
    permissions:
      contents: write
    steps:
      - uses: actions/checkout@master
        with: # We need to fetch enough commits to check if we've waited long enough
          fetch-depth: 12
      - name: Check if we've waited long enough (10+ commits)
        id: commit-count
        continue-on-error: true
        run: |
          [ '${{ github.event_name }}' != 'workflow_dispatch' ] || exit 0
          last_sha=$(git log --oneline --format=format:%H --grep="^chore: Generate README$" -1)
          echo "last_sha=$last_sha"
          if [ -n "$last_sha" ]; then # success if last_sha is empty
            count=$(git rev-list $last_sha..HEAD --count)
            echo "count=$count"
            [ $count -gt 10 ] || exit 1
          fi
      - name: Initialize README.md
        if: ${{ steps.commit-count.outcome == 'success' }}
        run: |
          [ -f README.tmpl.md ] || cp README.md README.tmpl.md
          printf '%s\n' "<!-- This file is generated from README.tmpl.md -->" > README.md
          cat README.tmpl.md >> README.md
      - name: CLOC
        if: ${{ steps.commit-count.outcome == 'success' }}
        uses: djdefi/cloc-action@6
        with:
          options: --md --report-file=cloc.md --hide-rate
        # Note: initial newline is required because files don't end with one
      - name: Update README
        if: ${{ steps.commit-count.outcome == 'success' }}
        run: |
          printf '\n' >> README.md
          printf '%s\n' '### Lines of code' "<sup><sub>Generated at commit $(git rev-parse HEAD)</sub></sup>" >> README.md
          cat cloc.md >> README.md
          rm cloc.md
      - name: Commit README
        uses: stefanzweifel/git-auto-commit-action@v4
        if: ${{ steps.commit-count.outcome == 'success' }}
        with:
          commit_message: "chore: Generate README"
          # Note: README.tmpl.md is needed in the first case
          file_pattern: README.md README.tmpl.md